tools/testing/nvdimm: add mock acpi_nfit_flush_address entries to nfit_test

tools/testing/nvdimm: add mock acpi_nfit_flush_address entries to nfit_test

Orabug: 22913653

In preparation for fixing the BLK path to properly use "directed
pcommit" enable the unit test infrastructure to emit mock "flush"
tables.  Writes to these flush addresses trigger a memory controller to
flush its internal buffers to persistent media, similar to the x86
"pcommit" instruction.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
(cherry picked from commit 9d27a87ec9e1317d368b1e5e3f4808078baa8c4c)
Signed-off-by: Dan Duval <dan.duval@oracle.com>